By Sandra Sproske

For years, experts have tried to warn consumers that if you’re getting something for free, you’re actually the product. And by “you,” experts generally mean, your “data.”

This means that the actual consumers of a “free” product are the companies that either pay to advertise to you, much like the old commercial TV model, or literally buy your data, often in the form of “customer profiles.”

F-Secure’s Chief Research Officer Mikko Hypponen often says, “Data is the new oil.” Personal information the lubricant that helps the Internet run, but the massive accumulation of data also threatens to create problems that will be difficult to contain or reverse.

Mikko notes he’d like to be able to pay Google for its services with money, but Google doesn’t even make that an option. It prefers your data. This may be because you’re worth so much to Google — $223 a year, according to a 2014 estimate — that the company doesn’t expect enough people would pay that much. Or maybe your data is priceless to a service with a parent company worth more than $600 billion.

Of course, Google isn’t the only one who wants your data. And at least anything the search giant does with your information you’ve already agreed to by accepting its terms and conditions, which you surely have memorized and discussed with your attorney.

What? You haven’t?

“It doesn’t matter what it says in the policy,” Mikko has said. “Nobody reads them.”

These sprawling documents are so ponderous that they’ve become such a joke that even some apps have been accused of not taking Apple’s terms and conditions seriously.

Over and over, you’ve been advised that you protect your private data.

That means that in addition to updated application and Internet Security software, you should use a trusted, VPN that doesn’t rely on ads and blocks online tracking. Be password smart and use two-factor authentication anywhere you can. You should also stick to trusted, well-reviewed apps from official app stores, refrain from posting personally identifiable information and pre-travel information on social media and lock up all your devices when not in use.

Unfortunately, complete privacy is difficult to attain online. But you should protect what you can and you should also know why you’re protecting your data.

Beginning with the most obvious reasons, here are five reasons you should do your best to keep your private data private.

1. Identity fraud or theft Protecting your devices and your accounts is essential for maintaining the security of your privately identifiable data and thus your financial identity. Phishing scams that lure you into offering your private data — such as taxpayer identification, national insurance number or credit card information — can be used to access your accounts or create false ones in your name. The more information you make public online, the more vulnerable you are to such scams, which are often crafted to resemble legitimate communication from your bank or other institutions. Avoid clicking on links in emails, especially unsolicited emails. And if anyone asks you for your private data online, contact that institution directly by phone to follow up.

2. Actual crime Posting your travel schedule in advance could make it easier for thieves to find an empty house to rob. Online stalking tied to actual theft is relatively rare, but what is increasingly common is cyberstalking with a criminal component — such as sextortion. “Sextortion cases involve what are effectively online, remote sexual assaults, sometimes over great distances, sometimes even crossing international borders, and sometimes…involving a great many victims,” the Brookings Institution reports. As the victims of this crime are often minors who may be scarred for life by being forced to share compromising images of themselves, law enforcement has began taking this sort of crime more seriously. Preventing this crime requires all the practical steps for protecting your data plus taking extra steps like covering up or disconnecting your webcam when it’s not in use and being extraordinarily careful about the sort or pictures you share online and store on your devices. The more personal information you make public, the easier it is for a stranger to ingratiate into your life and begin the process of harassing you online.

3. You can’t be sure how your data will be used against you. Last year, The Guardian reported that one of the largest insurance companies in Britain was examining Facebook profiles to help set the cost of consumers car insurance. Twitter wants your phone number to help secure your account but it also helps them match your account to an advertising profile that lets their advertisers know what your favorite breakfast cereal is. And even information we don’t actively share, such as our browsing history, is used by ad networks to feed us advertising that makes us more likely to spend money online. That’s by no means a crime on par with identity fraud or sextortion, but it is an example of how our private data can be used against us to diminish the control of our digital identities.

4. You can’t be sure what you’re giving access to. Even if you don’t overshare with your friends on Facebook, you still may be shocked to learn what you’re actually sharing with Facebook itself. The world’s largest social network seems to track your geographical location through GPS, Bluetooth or Wi-Fi signals. Snapchat doesn’t just allow itself access to the photos and videos you post but the entire contents of your device’s media library. And you agreed to this when you agreed to their terms and conditions. These giant corporations likely won’t use that information for anything other than their business, but this information could potentially be hacked and end up in the wrong hands. Or perhaps their are uses for it we can’t even imagine… yet.

5. The future. Before too long your dishwasher will likely have a web server in in it. Your toaster will connect to the internet, as will most anything you can plug in. This will provide manufacturers amazing abilities to track how their products are used for their benefit if not yours. And that data may end up being an asset that could be used to sell to another company looking for information about how to market to you a little better.

Your digital identity is tied to your data. Getting into the practice of securing it now will help protect you and your family now while preparing you for a future we cannot yet conceive.